Recent imaging and receptor studies have provided compelling evidence that a processing separation between body odors and non-body odors exists in the olfactory system. In both the visual and auditory systems, stimuli of high social and ecological relevance to the individual receive preferential treatment by perceptual systems and are able to modulate our behavior. Whether the olfactory system organizes stimuli according to this basic principle is not yet known. The overarching goal of this proposal is to establish whether the human brain processes body odors differently from non-body odors and to map the resulting behavioral consequences. The specific aims of this project are: 1) to establish whether exposure to a body odor modulates perception, as predicted by studies of comparative visual social stimuli, and 2) to establish whether body odor processing is preattentive and occurs without conscious recognition. Specifically, we will examine whether body odors are able to modulate physical arousal, neurological responses, and performance in behavioral tasks using, primarily, event-related brain potentials and behavioral measures. The proposed project will deepen our understanding of everyday social communication and widen our knowledge of the mechanisms underlying non- conscious interpersonal social communication. These studies will create groundwork for further investigations into the impact that various forms of olfactory deficits may have on social communication and into the links between those deficits and the mental health problems, such as depression, that afflicted patients often exhibit. PUBLIC HEALTH RELEVANCE: The proposed project will deepen our understanding of the role odors play in human interpersonal social communication. The knowledge gained through these studies may be used to investigate the impact that various forms of olfactory deficits may have on social communication and to explore the links between those deficits and the mental health problems, such as depression, that afflicted patients often exhibit.